They usually offer mouthwatering and unrealistic trades. Eg) Selling a $100 gift card at $50 when others are selling it at $80.
They are usually new members in a group.
They usually have little or no posts in a group.
They are always in a hurry during transactions.
They will block your number immediately after you transfer money to them.
They sometimes come in the name of religion, calling themselves Child of God. Holy etc... All are lies.
Some of them engage in legit exchange for some period in order to earn your trust and they go rogue.
They use 2 numbers on telegram and WhatsApp groups. They use one number to convince the whole group that he's legit and they use the other number to scam and ripe.
BE WISE